The rise of Web 2.0 and social networking sites has led to an increased importance of the role of the users throughout the requirements engineering (RE) process. As the users of social networking sites (SNS) are typically unknown and located in various locations, integrating the users in the requirements engineering process is complicated. Social research networking sites (SRNS) as a new and developing subcategory of social networking sites especially need to take this increased role of the users into account, as the users have even more specific needs due to the various research-supporting functionalities expected. However, existing approaches to requirements engineering do not consider the circumstances prevailing in social networking sites. Therefore, this paper aims to provide guidelines how to conduct RE when developing a social networking site. To achieve that goal, existing approaches in the literature are analyzed. Furthermore, qualitative interviews with experts in the field of RE and with the founders of the leading SRNS have been conducted to compare the as-is state concerning RE with the target state. Resulting from this investigation, a model for the integration of users in the RE process is proposed. Furthermore, requirements elicitation and feedback methods are evaluated in terms of their adequacy in the context of SNS in general and for specific process phases in particular. As the continual improvement of SNS is of particular relevance for the long-term success of these platforms, a model for the continuative RE in SNS is provided.